The major objective of the proposed research is to study the impact of early-life exposures to common urban pollutants on neurobehavioral development and asthma in a sample of children living in three low-income, minority communities of New York City (Central Harlem, Washington Heights and the South Bronx). Using a molecular epidemiologic approach with monitoring, biomarkers, and clinical assessments at serial time points, we will extend our study of African-American and Latina urban mothers and children in order to follow the cohort through child age 11 years to assess the longer-term impact of exposures on child health and developmental outcomes. The exposures of concern include airborne polycyclic aromatic hydrocarbons (PAHs) and orgnaophosphate pesticides such as chlorpyrifos (CPF). The first Specific Aim (Neurodevelopmental) builds on our prior findings and proposes to evaluate relationships between early exposures (PAHs and CPF) and longer-term neurodevelopment, in order to assess the persistence of neurotoxic effects into the school years, identify effects that may emerge over time, and delve more deeply into the behavioral domains to better understand the significance of behavior problems observed in the preschool years. The second aim (Asthma) also builds on our previous findings with respect to risk factors for asthma. We will repeat the assessment of immunoglobulin (lg)E at ages 5, 7, and 9 and obtain measures of lung function and airway inflammation, and a physician-diagnosis of asthma between ages 5 and 7 years. We will also assess the association between becoming overweight in the first 5 years of life and the development of IgE, airway inflammation, and asthma in childhood. The research will consider the effect of known determinants of disease and potential confounders, including other toxic exposures and demographic factors. By using a multidisciplinary approach to understand the complex pathogenesis of developmental disorders and asthma that impose such a heavy burden on inner-city children, we anticipate that the proposed research will have important implications for prevention.